ActionScript 2.0 :: Add The BlockOneUp Variable To The _root.Block?

I need some help with some variable problems. (AS2)

Code:
if (_root.Block+blockUpOne.dead == false) {
surroundingBlocks++;
}
I'm targeting a duplicated mc from another duplicated mc. The 'blockUpOne' is the variable of the number on the end of the duplicated mc (the "i" variable when the mc was created 20, the amount of blocks in the grid across). Basically I'm trying to target a block on top of the one with the code on. I need to add the blockOneUp variable to the _root.Block to made a string which targets a duplicated mc above the one with the code. Even more basically, I want to target an mc by adding a variable to the targeting code.

Example:
Block above: Block34
Block with code: Block54
if(_root.Block+(54-20) is alive){
do stuff
}